[evol] commands management rework #2: moved command parsing out of the Mail class and created new classes to handle it
[evol] added setup.rb installer, with hooks to generate locales and a 'lib/cyborghood/config.rb' file having a new CyborgHood::Config providing with installation paths, and created CyborgHood::Info to contain software general information (rakefile build-depends are then reduced to the minimum)
[evol] added replay email signature (textual, not gpg one), and made a few Postman methods private btw
[fix] gettext domains are binded correctly now (using a new PostmanHome submodule to separate domains easily)